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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Innovative approaches to recycling of small and electric motors from end-of-life vehicles, electric bicycles and industrial machinery

Link, Rainer January 2016 (has links)
Recycling and recovery of materials and energy from waste is a key factor to mitigate virgin material demands and reduce resource consumption by utilising waste as a resource for new products. However, some critical materials, such as neodymium, are barely recycled because of missing information on amount and disposition of these critical materials within the waste streams. The goal of the study is to quantify recycling potentials from small and electric motors originating from end-of-life vehicles (ELV), electric bicycles and industrial machinery in Germany and the EU with focus on currently lost rare earth elements. Furthermore, innovative approaches to improve recycling of these motors shall be investigated. Therefore, a calculation model to predict current and future waste streams and the incorporated recycling potentials has been developed. The results show an increasing trend of recycling potentials from small and electric motors for all waste streams. The recycling potential of neodymium is estimated at a range of 150 t to 240 t in 2020 in Germany. However, data inaccuracy and the calculation model are likely to cause overestimation of actually available recycling potential and have to be interpreted carefully. In conclusion, disassembly of small and electric motors from ELV and electric bicycles in combination with a subsequent specific recycling process has been identified as promising to improve utilisation of the recycling potentials of rare earth elements from small and electric motors. However, in case recycling quotas are the prior goal of improvement, the application and further optimisation of post shredder technology is more relevant.
52

Oil Cooling of Electric Motor using CFD

Al Shadidi, Kamilla January 2014 (has links)
This thesis investigated the heat transfer of internally oil cooled rotors in permanent magnet electric machines which are, among other things, used in hybrid vehicles or zero emission vehicles. The magnets become sensitive and can be demagnetized at high working temperatures, hence the need of cooling. The scope of this work included CFD simulations in STAR-CCM+. Three different 3D multiphase models simulating the oil propagation in the rotor were performed. A Lagrangian multiphase model combined with a fluid film model was the most suitable model for simulating the spray of the oil and the film thickness along the inner rotor wall. It was noticed that periodic boundaries caused problems for the fluid film model, therefore a complete geometry was preferred over a truncated model. The 3D solutions provided thicker film thicknesses than the analytical solutions from the fluid film thickness theory. The maximum analytical thickness was of the same order of magnitude as the surface average film thickness provided by the multiphase models. This thickness was assumed to be constant when used as the base for the fluid region in the 2D one-phase models.The study showed that aluminum was the most suitable rotor material due to its high conductive capacity, which provided a more even distribution of the temperature in the solid and hence resulted in lower overall temperatures. The cooling power increased linearly with the volumetric flow rate, however the heat transfer coefficient decreased for the higher flow rates. A volumetric flow rate of 10dl/min was recommended. A 2D model was compared to a preliminary experiment and showed that these were not correlated. The conclusion was that more experiments and simulations are needed in order to confirm the validity of the 2D model.
53

Development of a Dynamic Thermal Model for the Rear Electric Motor System on the Ohio State EcoCAR Mobility Challenge Vehicle

Loyd, Kerri Aileen January 2021 (has links)
No description available.
54

DESIGN AND IMPLEMENTATION OF LOW COST DE-NOISING SYSTEMS FOR REAL-TIME CONTROL APPLICATIONS

Khorbotly, Sami 02 October 2007 (has links)
No description available.
55

Calculation model for selecting electric motors on pallet conveyors

Carling, Jakob January 2022 (has links)
At Swisslog there is no up to date model for selecting the electric motors for their conveyor elements. The current model and measurements are about 20 years old and the motors and conveyors have changed in that time. To get a better picture and basis for the selection of the electric motors a calculation model for the torque requirement for different pallet weights was produced in this work. The model was further expanded to involve the calculated overhung load, the root mean square power and the permitted switching frequency for the motors which would also aid in the decision of which motor would fit for each application. To verify the model a number of different tests were completed to measure the actual torque from the motor when the conveyors were in use. The model and the testing results had a reasonable resemblance. From the calculations an excel document was also developed which used the calcualtions as a basis to give a selection of motors that can function at a number of different pallet weights and conveyors. The excel document implements all of the calculations from the models to enable a simple choice of motor for the specific conveyor element for the designer at Swisslog.
56

Multi-pole permanent magnet motor design and control for high performance electromechanical actuation in all electric aircraft

Bindl, Jared C. 01 January 2010 (has links)
The evolution of aircraft has led into a large increase in the demand for electrically integrated subsystems. Part of this demand is the transformation of a centralized hydraulic systems to independently operated electrical subsystems. The result of this overhaul will decrease aircraft weight, increase reliability, reduce aircraft lifetime maintenance and cost, and help to increase the control of power distribution. This thesis proposes the design methodology of a multi-pole permanent magnet (PM) motor with a capability to operate at high temperature. High temperature capability is one of the key requirements to implement electromechanical actuation for aircraft flight control, replace hydraulic actuation system, especially in tactical military aircraft, due to the hot environment and lack of heat sink. Temperature effects on motor materials are reviewed. The need for high power density is considered in the design. The motor design is confirm by ANYSYS RMXprt software. Along with the motor design, a voltage control method is also designed for the motor. Integrated electrical simulation results of the motor and controller to follow highly dynamic flight profiles are provided to show the stroke tracking, input power (including regenerative power), and winding copper loss. Experimentation set-up of EMA and experimental uncertainties are also discussed.
57

Analysis of the Dynamic Interferences Between the Stator and Rotor of a Refrigeration Compressor Motor

Thompson, Swen 07 May 1997 (has links)
This thesis involves the development and study of a finite element model of a hermetic, single-vane compressor and a single-phase alternating current induction motor assembled in a common housing. The manufacturer of this unit is experiencing a high scrap rate due to interference during operation between the stator and rotor of the motor. The rotor shaft of the motor is non-typical because of its cantilever design. The finite element model was first subjected to eigenvalue analysis. This revealed that the interference producing displacements were not the result of torque application to the rotor at a frequency close to an eigenvalue of the mechanical system. After a review of the literature and discussions with Electrical Engineering Department faculty possessing extensive motor experience, it was surmised that the physical phenomenon causing the rotor displacement was unbalanced magnetic pull. This phenomenon occurs in the air gap of rotating electric machines due to eccentricity in the air gap. The model was then subjected to simultaneous harmonic force inputs with magnitudes of unity on the rotor and stator surfaces to simulate the presence of unbalanced magnetic pull. It was found that the rotor shaft acts as a cantilever beam while the stator and housing are essentially rigid. The displacements due to these forces were examined and then scaled to develop the motor parameters necessary to produce the radial forces required for stator/rotor interference. Several recommendations were then made regarding possible solutions to the interference problem. / Master of Science
58

6/14 Switched Reluctance Machine Design for Household HVAC System Applications

Kasprzak, Michael January 2017 (has links)
With the unstable cost and supply of rare earth materials used in permanent magnet electric machines, many alternative machine types are being studied which are suitable for different applications. The focus of this thesis is the design of a novel 6/14 switched reluctance machine which can be fitted in a residential heating, ventilation, and air-conditioning (HVAC) application based on measured performance characteristics of an existing surface mount permanent-magnet synchronous (SMPS) machine. Residential electric motor applications are reviewed and in particular - furnace blower motor appliances. The fundamentals of switched reluctance machines are discussed, including the mechanism, operation, and control strategy. A SMPS motor which is commercially available for retrofitting into residential HVAC systems is analyzed to find its performance characteristics through disassembly, inspection, and dynamometer bench testing. The design of a novel 6/14 SRM optimization process is outlined to investigate the effect of changing the geometry values within the motor on the performance characteristics, while keeping within the size constraints of the original motor. A novel 6/14 SRM design is presented which is capable of achieving the target goals in the desired operating conditions. Further suitability testing is performed in terms of thermal analysis of the motor in the peak and continuous operating condition and mechanical stress analysis of the rotor under various rotational speeds. The full CAD assembly of the motor is designed including components from the original SMPS motor to allow for fitting in the same HVAC application. / Thesis / Master of Applied Science (MASc) / With the unstable cost and supply of rare earth materials used in permanent magnet electric motors, many alternative machine types are being studied which are suitable for different applications. The focus of this thesis is the design of a novel 6/14 switched reluctance machine which can be fitted in a residential heating, ventilation, and air-conditioning (HVAC) application based on measured performance characteristics of an existing surface mount permanent-magnet synchronous (SMPS) machine. Switched reluctance machines have a number of benefits over permanent magnet machines including that they do not have permanent magnets, are less sensitive to high heat scenarios, have lower manufacturing costs, are more robust, and are generally capable of higher operating speeds. Residential electric motor applications are reviewed and in particular - furnace blower motor appliances. The fundamentals of switched reluctance machines are discussed, including the mechanism, operation, and control strategy. A SMPS motor which is commercially available for retrofitting into residential furnace systems is analyzed to find its performance characteristics through disassembly, inspection, and dynamometer bench testing. The design of a novel 6/14 SRM optimization process is outlined to investigate the effect of changing the geometry values within the motor on the performance characteristics, while keeping within the size constraints of the original motor. A novel 6/14 SRM design is presented which is capable of achieving the target goals in the desired operating conditions. Further suitability testing is performed in terms of thermal analysis of the motor in the peak and continuous operating condition and mechanical stress analysis of the rotor under various rotational speeds. The full 3D CAD assembly model of the motor is designed including components from the original SMPS motor to allow for fitting in the same HVAC application.
59

An Integrated Design Approach of Rotor Assembly for Radial Flux Surface-Mounted Permanent Magnet Synchronous Motors

Manikandan, Akshay January 2023 (has links)
Enhancing the dependability and power density of a SPMSMs is crucial for its extensive utilization in the automotive and aerospace sectors. One major concern regarding these machines is the significant thermo-mechanical loads experienced by the overall rotating assembly due to high rotational speeds and a wide operational temperature range from $50^\circ C$ to $150^\circ C$. This poses a considerable challenge in maintaining structural integrity among the components. Redesigning components to reduce assembly complexity and weight necessitates careful consideration of boundary conditions and contact modeling to prevent catastrophic failures like magnet fly-by conditions. To reduce model complexity, a simplified approach involves integrating the hub and shaft; both machined from AISI 4340. Additionally, the application of a carbon fiber sleeve is investigated through 3-dimensional composite modeling to enhance structural integrity. The primary objective of this thesis is to scientifically justify the design and validation of an integrated rotor hub and shaft using efficient FEM and integration strategies, with the aim of maximizing the durability of a $150kW$ radial flux SPMSMs spinning at $20,000 rpm$. The integrated topology optimization is evaluated using a multiphysics platform alongside studies on motor assembly eigenfrequency. By employing the integrated approach and utilizing AISI 4340 for both the shaft and rotor hub, a weight reduction of $1.84kg$ is achieved, eliminating the need for standard components such as balancing end clamp plates, locknuts, and washers. Furthermore, introducing a carbon fiber sleeve enhances structural integrity, thereby reducing adhesive stress. The design and optimization of the rotating components ensure that the maximum von Mises stress is $50\%$ lower than the material's yield strength. Reduced masses lead to lower centrifugal forces, thereby diminishing radial stress and promoting component and assembly stiffness. / Thesis / Master of Applied Science (MASc) / This thesis aims to increase the reliability and power density of a surface-mounted permanent magnet synchronous machine (SPMSMs), a commonly used traction motor in the automotive and aerospace industries. One of these machines' main challenges is designing their components to withstand the high mechanical loads caused by their fast rotational speeds. The studies performed in this thesis use a computer modeling technique called Finite Element Modeling (FEM) to strategize and design an integrated rotor hub/shaft by maximizing the durability of a 150kW radial flux SPMSMs rotating at 20,000 rpm. Upon evaluating the integrated design using a variety of physics-based simulations, the design was found to save 1.84kg in weight, reducing centrifugal forces and improving the overall stiffness of the motor assembly. This research could lead to more efficient and durable electric SPMSMs for various applications.
60

MOTION-CONTROL SYSTEM OF BENCH-TOP CT SCANNER

PATEL, TARPIT KAUSHIKBHAI January 2008 (has links)
No description available.

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